POS1378 ARTHRITIS IN PATIENTS WITH FAMILY MEDITERRANEAN FEVER
Authors: S. Yenigun, A. Y. Ayla, S. N. Baspinar, M. B. Yuzbasioglu, A. Alkan, I. Durucan, M. Kirman, B. C. Polat, S. Ergun, H. Ozdogan, S. Ugurlu
Journal: Annals of the Rheumatic Diseases (2022)

Background Familial Mediterranean fever (FMF) is an inherited autoinflammatory disease characterized by recurrent episodes of fever and serositis. Arthritis is one of the most common attack manifestations. Arthritis in FMF is usually in the form of acute mono- or oligoarthritis of the large joints of the lower extremities. While acute attacks of arthritis usually heal without causing permanent deformity, the severe, long-lasting form of chronic arthritis can last for months or even years and result in permanent deformity. Objectives In this study, we described the characteristics of joint involvement in FMF in a single cohort. Methods The medical records of patients with joint involvement from our cohort of 2350 patients who were diagnosed with familial Mediterranean fever were retrospectively scanned through the files and hospital database. The prevalence, demographic information, genetic test results, clinical features, features of joint involvement, treatments and responses, acute phase values in the attack and remission periods, and family history of patients with joint involvement were recorded. Results 953 patients (n=953) from a total of 2350 patients had arthralgia or arthritis (40%). In our study, the male/female ratio was found to be 0.49 (male n=316, female n=637). The number of patients who underwent genetic testing was 787 (82%), and 702 (89%) of these patients had mutations in the MEFV gene. The most common pathogenic mutation is the M694V mutation with a rate of 43%. Concomitant diseases and their frequencies are shown in Table 1, the most common accompanying disease was spondylarthritis at a rate of 27%. Arthritis was present in the first attack in 55% (n=531), while arthritis was found in the ongoing attacks in 45%. The duration of the attack was between 24-96 hours in 77% (n=837) of the patients, and the duration was longer than 96 hours in 23% (n=116). The most common finding accompanying the attacks was exercise-related leg pain. Family history was present in 61% (n=580). 73% of the patients (n=696) were involved in the ankle and 51% were involved in the knee (n=492). The incidence of sacroiliitis was 14% (n=142). As for the number of joints, 91% of the patients had mono- and oligoarthritis. Asymmetric involvement was detected in 77% of the patients. Red arthritis was present in %73 of our study group. HLA-B27 was examined in 185 patients, 24 of them were positive (12%). It was found that 43% of the patients had treatment changes due to arthritis. Colchicine dose increases and changes were performed in 32% of these patients. NSAIDs were started in 21%, corticosteroids in 15%, DMARDs in 12%, anti-TNF in 10%, and anti-IL-1 in 8%. The mean dose of colchicine was as 1.56 ± 0.5 mg. Unresponsiveness to colchicine was found in 21% (n=122). Table 1. Concomitant diseases of our FMF cohort Conclusion FMF diagnosis should definitely be considered in people with red mono-oligoarthritis in the large joints of the lower extremities. One of the most important features of joint involvement in FMF patients is the short duration of arthritis. The accompanying effort-related leg pain is an important symptom that should suggest FMF. In patients with a diagnosis of FMF and arthritis, the required colchicine dose in the treatment and the rate of colchicine unresponsiveness are higher than in other attack types. The incidence of sacroiliitis and spondyloarthropathy increases in patients with FMF, and joint involvement features are similar. FMF should be considered in the differential diagnosis of patients with inflammatory low back pain. Disclosure of Interests None declared